Understanding renewable energy

What is renewable energy?

There are many ways that we can produce usable energy to power our homes and cars, and this energy can be created using resources that generally fall into one of two categories: renewable and non-renewable.

Renewable resources are ones that nature can consistently replenish, such as wind, water and sunshine. These things are readily available to us and, no matter how much we use, they will always be replaced, though the energy created in this way is often much harder to store for later. Non-renewable materials are ones that could eventually run out, such as coal, gas and oil. Although these fossil fuels can generate lots of energy quite cheaply, these aren’t sustainable and could be depleted altogether if we continue to exhaust the planet’s supplies. Using these materials to create energy can also result in large volumes of greenhouse gases being released into the atmosphere, warming up our planet and causing potentially catastrophic consequences in the future.

Therefore, using renewable energy sources is increasingly seen as the preferred option as they don’t pollute the environment with harmful emissions.

What are renewable energy sources?

So now that we know what renewable energy is, what are some examples and how are they currently used on our planet to generate electricity? The most common forms of renewable energy are solar, wind, tidal, geothermal and hydro.

Solar

For millions of years, the sun has produced heat that warms up our planet and helps plants to grow, but now it can be harnessed to heat our homes and businesses or power devices. The energy is collected via photovoltaic cells that use the light to generate electricity.

Solar farms can produce enough electricity to power hundreds or even thousands of homes. Solar panels that are installed on the roof of your home will produce significantly less electricity, but can still reduce your electricity bills. If you use solar power to create electricity for appliances such as a heat pump or electric boiler, you could heat your home emission-free and without spending any money on gas.

Wind

It’s likely that you’ve seen wind farms when driving through rural or coastal places. They’ve become common in the UK and are an efficient way of generating electricity. The turbines have large blades that spin when it’s windy. As they spin, the movement feeds an electric generator to produce electricity. These turbines can only produce significant amounts of electricity when it’s windy, which is why you often find them positioned near the coast, out at sea or in exposed rural areas. This form of electricity production is the UK’s biggest source of renewable energy and accounts for around 20 per cent of the total amount produced.

Tidal

Tidal energy uses the natural power and movement of the waves to create energy. Just like wind turbines turn to start up a generator that can produce electricity, turbine generators can be located in the sea that are turned by the movement of the waves. Unlike solar and wind power, the tide and currents can be predicted much more easily, meaning that this kind of energy can be controlled more easily. It is also more obvious when there will be periods of low-energy generation due to a low tide.

While this form of generation is less common than either solar or wind power, it’s being developed so that we could make more use of it in the future. 

Geothermal

While we’ve discussed how electricity can be generated through water, sunshine and wind, the one method we haven’t yet discussed is heat. However, using the earth’s natural heat, we can generate energy for all sorts of purposes. We’re all aware that far below our feet is very hot magma. Sometimes, when a crack known as a geyser appears, steam can erupt out of the ground. This steam can be used to move turbines within generators to produce electricity. Geothermal power plants are more commonly found in the US, however other countries are also working to increase how much energy is produced in this way, including Turkey and Kenya.

Hydropower

While tidal power uses the natural movement of the sea to produce electricity, hydropower uses the currents of streams and rivers. Surprisingly, hydropower is one of the biggest sources of renewable energy, particularly in places such as China, Canada and Russia.

The water can be controlled efficiently through the building of large dams. This reduces the risk of being able to create sufficient power some days and none on others when water movement is steadier and slower. This can make this source of renewable energy slightly more reliable.

Why is renewable energy important?

The UK government set a target under the Climate Change Act 2008 to reduce carbon emissions by 100 per cent by 2050 (quoted as of 18th March 2020). The way in which we produce much of our electricity at the moment involves burning coal. This produces various greenhouse gases, including carbon dioxide, which is gradually warming up our planet. If the Earth warms up by just one and a half degrees celsius, this would be considered the threshold for dangerous climate change.

To prevent us from reaching this threshold, we need to reduce the carbon emissions that are being produced, and the best way to do this is with renewable energy. Using solar, wind, tidal and other such forms of power creates zero emissions and is significantly better for our environment.

This is why various schemes and grants have been created, including the Renewable Heat Incentive (RHI). and green homes grants scheme. If you are eligible, you could earn a small amount of money from the government as an incentive to offset some of the upfront costs involved in heating your home with renewable energy. These incentives can change over time.

How much of our energy is renewable?

Data released in June 2019 showed that around 35.8 per cent of the electricity being produced in the UK is from renewable energy sources, with gas, a non renewable source, slightly ahead of this at 41.9 per cent. Coal usage is shrinking in preparation for a complete phaseout of coal plants by 2025. 

Wind is currently the biggest renewable producer of electricity in the UK, closely followed by solar energy. As a proportion of energy production in the UK the solar sector has doubled in just four years and, as of July 2019, there were over one million solar installations in the UK. 

Sources:

www.nrdc.org/stories/renewable-energy-clean-facts#sec-whatis
www.nbcnews.com/mach/science/what-are-fossil-fuels-ncna983826
www.bbc.co.uk/bitesize/guides/zh7hvcw/revision/1
www.theguardian.com/business/2019/oct/14/renewable-electricity-overtakes-fossil-fuels-in-uk-for-first-time
www.bbc.co.uk/news/science-environment-48596775
www.carbonbrief.org/analysis-uk-renewables-generate-more-electricity-than-fossil-fuels-for-first-time